Automatic sampling device



'July 26, 1949. I

G. C. FAIRBAIRN AUTOMATIC SAMPLING DEVICE 2 Sheets-Sheet 1 Filed Sept. 15, 1947 A 'T'TORNEYE M INVENTOR. & GEORGE QFA/PBA/PN BY/QW y 6, G. c. FAIRBAIRN 2,477,513

AUTO-MATIC SAMPLING DEVICE Filed p 1 7 2 Sheets-Sheet 2 INVENTOR. GEORGE O. FZ/RBA/Q/v A TTORNE Y5 Patented July 26, 1949 TENT OFFICE AUTOMATIC SAMPLING DEVICE George C. Fairbairn, Port Arthur, Tex., assignor to The Texas Company, New York, N. Y., a corporation of Delaware Application September 13, 1947, Serial No. 773,879

Claims.

The invention concerns an automatic sampling device for use in obtaining samples of fluids moving through a pipe line.

It is an object of the invention to provide means for obtaining samples which are representative of gases or liquids passing through a pipe line during a given time interval.

. It is a further object ofthe invention to provide an automatic sampling device adapted to take samples intermittently at time intervals corresponding to the rate of flow through the pipe line, each of the samples being of predetermined volume;

It is customary to measure the rate of flow through a pipe line by means of flow meters of either the displacement type or the differential type. The device of the invention includes a flow meter of the differential type. In a copending application, Serial No. 773,878, filed concurrently herewith, now Patent No. 2,461,045, I have disclosed and claimed an automatic sampling device which includes a displacement type meter.

The device of the invention includes a sample draw-off line connected to the pipe line, a shutoff valve in the sample draw-oh line, and valve operating means adapted to open and close the shutoff valve. A diiierential type flow meter installed in the pipe line is responsive to fluctuations in rate of flow through the pipe line A primary timing mechanism actuated by the flow meter is adapted to complete an electrical circuit intermittently at time intervals corresponding to the rate of flow through the pipe line. A secondary timing mechanism actuated by a constant speed electric motor is adapted to complete another electrical circuit and to break the last mentioned circuit after a predetermined period of timehas elapsed during which period the sample is withdrawn. The valve operatin means and the secondary timing mechanism are actuated by first one and then the other of the electrical circuits.

In the device of the invention the primary timing mechanism, which is actuated by the differen tial type flow meter may comprise a mercury switch mounted on a lever, a solenoid adapted to act upon the lever to tilt the mercury switch, a vacuum tube relay adapted to control the operation of the solenoid and contact points mounted on the rotating disc and the pen of the meter adapted to complete the grid circuit of the vacuum tube relay. Concentric rows of contact points may be mounted on the rotating disc, the number of contact points in. the several rows increasing progressively from the center of the disc out- Cir wardly, the arrangement being such that the pen engages the contact points on the rotating disc at more frequent intervals as it swings outwardly from the center of the disc in response to increases in flow rate.

The valve operating means which opens and closes the shutoff valve may comprise either a solenoid or a constant speed electric motor equipped with speed reducing gears.

The secondary timing mechanism, which is ctuated by a constant speed electric motor, may comprise a switch adapted to be opened and closed by an eccentric driven by the constant speed motor through speed reducing gears. When the valve operating means comprises a constant speed electric motor and speed reducing gears the secondary timing mechanism may be actuated by the valve operating means, the eccentric which constitutes a part ofthe timing mechanism being mounted directly on the valve stem and actuating a reciprocating rod which in turn acts upon a lever on which a mercury switch is mounted, to tilt the mercury switch.

The invention will be better understood from the following description and the accompanying drawing, in which:

Fig. l is a diagrammatic view in elevation of one form of the invention in which the valve operating means comprises a constant speed electric motor and speed reducing gears, and in which the secondary timing mechanism is actuated by the valve operating means.

Fig. 2 is a diagrammatic view in elevation of a modified form of the invention in which the valve operating means comprises a solenoid and the secondary timing mechanism comprises a switch adapted to be opened and closed by an eccentric driven by a constant speed motor through speed reducing gears. The apparatus shown in Fig. 2 may be substituted for the portion of the apparatus shown below the dotted line XX of Fig. 1, the points A, B and C being common to both views.

Fig. 3 is an enlarged plan view taken on the line to the might.

'3 flow through the pipe line. Contact points 2 mounted on the rotating disc 3 and the pen 4 of the meter are adapted to complete the grid circuit of a conventional vacuum tube relay comprising a triode 5 and a plate relay 6. As shown in Fig. 4, concentric rows of contact points 2 may be mounted on the rotating disc 3, the number of contact points 2 in the several rows increasing progressively item the center of the disc 3 outwardly, the arrangement being such that the pen t engages the contact points 2 on the rotating disc 3 at more frequent intervals as it swings outwardly from the center of the disc 3 in response to increases in flow rate so that the sampleswill be taken more frequently as the flow rate increases.

The vacuum tube relay 6 controls the opera ticn of a solenoid I which acts upon a'lvr '8 to tilt a mercury switch 9, the arrangement being such that an electrical circuit is completed through the mercury switch 9 each time the pen (l of the meter'engages' one of the contact points 2 on the rotating disc 3. The foregoing arrangement is referred to as a primary timing mechanism. 1 v

A ball type shutofi valve in isinstalled in a sample draw-off line' .ll leading from the pipe line lid to be sampled; The shut-off valve It is operated by a constant speed electric motor i2 through speed reduc n g8ars' l3. An eccentric Id mounted on the stem .15 or the shntofi valve IE3 aetuates arecipreoatingifiocl 16 which in turn acts upon'a lever I! oil-which a single through mercury switch IB isinoiinted, toitilt the mercury switch It. {The rod H5 is normally urged toward the eccentric by a coil spring .lta This arrangemen-t is referred to'as-a secondary timing mechanismranel is equivalent; to jihe secondary timing mechanism shown in Fig.- .2 which will be described hereinafter.- o} e H e e v Lead wires are provided which connect the constant speed motor 2 to a source of electricity. One of the lead wires [9 is connected-directly to the motor l2,- the 'other wire 20 being connected to the motor 52 through two separate circuits 2i and 22. Gn-e of thecircuits 2-l is adapted to be completed by themerenryswitch-fl and the other circuit-22 is adapted to be completed by the mercury switchlB. 4

As shown the drawii igl bethof the mereury switches 9 and I8 are open and no current flows to the motor i2.-' -.As soon as the pen lengages one of the contact points ion the rotating disc 3 the plate. relay 6 will close andthe solenoid i will be energizedtecempletethe electrical circuit 2i throughthe mercury switch 9. The motor i2 will then be started and while thevalve' ill is opening the ccentric IA will turn, thereciprocating rod- IB moving to the right. The other electrical circuit gi will be completed when the mercury switchlt tiltsdownwardly to the'ri-ght. The motor 12 will continue to run for a precis termined period oftime, until the last-mentioned electrical circuit is broken by the action of the eccentric] l, the reciprocating-rod l 9 being moved to the left and acting upon the lever 11 to tilt the mercury switch !8 to inoperative position again as shown in the drawing. As'shown in the drawing, the shutoff valve Hi is in closed position. It is opened and closed during each operation to permit a sample to be withdrawn through the sampling line I I. It is to be understood that the pen 4 remains in engagement with one of the contacts 2 untilafter the switch 9 has been tilted It will be seen from the foregoing that as soon as the pen 4 engages one of the contacts 2, a circuit will be completed through the motor I2 which will start opening the valve In and also tilting the switch I8 downwardly to the right. As soon as the switch l8 closes, the circuit will be maintained through the motor l2 even though the pen v l subsequently becomes disengaged from its contact 2. The motor .12- will'thuscontinue to run, permitting a sample to be drawn through the draw-off pipe il until the cam l4 and rod IS have tilted the switch Hi to its open position. The secondary timing mechanism, therefore, serves to time the period when the valve It is open and thus g'overn the amount of fiuid'withdrawn through the sample line regardless of the fact that the pen l may not remain in engagement with one of the contacts 2 for a sufiiciently long period. 2

Referring to the modification shown in Fig. 2 of the drawing, a solenoid operated valve 33 is installed in thesaniple draw cfr line H. The secondary timing mechanism comprises a switch 2 adapted to be opened and closed by an eccentric 2 5 driven by aconstant Sliced motor 25 through speed reducing gears '21;

As statedhereinabove-tlie' apparatusof Fig. 2 may be substituted for the apparatus shown he- 710w the dotted line 32:): of Fig. 1, the points A,

B and C se ing common to both news.

With the apparatuspf I|ffig."2 substituted for that shown below line 'x X or Fig. 1 the opera tion is similar to that already described.

When the pen 4 engages one of the contacts 2 switch 9 will close permitting current to flow to the lead connecting the solenoid 23 and the motor 25. The sole'fioid'will cpenits Valve and. at the' same time tne-ecccntnczs will turn to perniit'tl'ie swithl i to close, thus permitting current to pass through this switch to the load con necting the solenoid 23 andthe motor 26 and this circuit will remain closed the eccentric zi has made acomplete revolution, whereupon it will again open the switch 24. Thus, by proper selection or theep ea of themotor 2s and the reduction gear 21 the solenoid 23 will be caused to maintain the valve-in the sampling line H open until the desired amount ofsample has been with I drawn.-

Obviously many modifications and variations of the invention, as hereinbefore set forth, may be made without departingfrom the spirit and scope thereof, and therefore only such limitations should be imposed as are indicatedin the appended claims.

I claim: r a

1. An automatic sampling device ioruse in obtainin samples of a. fluid flowing through a pipe v line at intervals the tfrequency ofwhich vary in accordance with the flow rate through said pipe line comprising a sample draw-01f line connected to said pipe line, a .rotatable'vaIve in'said draw-'- ofi line, electrical actuating means for said valve, a device responsive to the now through said pipe .line, a source of electricity, an electrical circuit connected to said valve actuating means, a primary timing device actuated by said flow responsive device for intermittently connecting said source to said circuit, a secondary timing device for maintaining saidcircuit closed for predetermined intervals after it is first closed by said pri mary timing device, and-imeans for actuatin said secondary timing device comprising an eccentric connected to said valve :torotate therewith and a drive rod connecting said eccentric and said sec ondary timing device.

2. An automatic sampling device for use in obtaining samples of a fluid flowing through a pipe line at intervals the frequency of which vary in accordance with the flow rate through said pipe line comprising a sample draw-off line connected to said pipe line, a valve in said draw-on" line, electrical actuating means for said valve, a rotating face meter responsive to the flow through pipe line, a source of electricity, an electrical circuit connected to said valve actuating means, a primary timing device for intermittently closing said circuit to connect said source to said valve actuat-- ing means, said primary timing device including a pen arm on said meter, a plurality of contacts on the rotating face oi said meter, a tiltable rnercury switch. normally biased to its open position and connected in said circuit between said source and said valve actuating means, an electro-magnet adapted when energized to tilt said switch to its closed position, and means for energizin said magnet when said pen arm engages one of said contacts, and a secondary timing device for maintaining said circuit closed for predetermined intervals after it is first closed by said primary timing device.

3. An automatic sampling device for use in obtaining Samples of a fluid flowing through a pipe line at intervals the frequency of which vary in accordance with the flow rate through said pipe line, comprising a sample draw-off line connected to said pipe line, a valve in said draw-oil line, electrical actuating means for said valve, a rotating face meter responsive to the flow through said pipe line, a source of electricity, an electrical circuit connected to said valve actuating means, a primary timing device for intermittently closing said circuit to connect said source to said valve actuating means, said primary timing device including a pen arm on said meter, a plurality of contacts on the rotating face of said meter, a

relay having an energizing winding and contact points, a second source of electricity, said pen arm, contacts, relay winding and second source being connected in a second circuit adapted to be closed when said arm engages one of said contacts, a tiltable mercury switch normally biased to its open position and connected in said circuit between said source and said valve actuating means, an electro-magnet adapted when energized to tilt said switch to its closed position, said electro-magnet, said relay contacts and said first electrical source being connected in a third circuit adapted to be closed when said relay winding is energized, and a secondary timing device for maintaining said circuit closed for predetermined intervals after it is first closed by said primary timing device.

4. An automatic sampling device for use in obtaining samples of a fluid flowing through a pipe line at intervals the frequency of which vary in accordance with the flow rate through said pipe line comprising a sample draw-off line connected to said pipe line, a rotatable valve in said drawoff line, electrical actuating means for said valve, a device responsive to the flow through said pipe line, a source of electricity, an electrical circuit connected to said valve actuating means, a primary switching device actuated by said flow responsive device for intermittently closing said circuit to connect said source to said valve actuating means, a secondary switching device for maintaining said circuit closed for predetermined intervals after it is first closed by said primary switching device, said secondary switching device including a tiltable mercury switch connected in parallel to said primary switching device, an arm on said switch and means for tilting said switch comprising an eccentric connected to said valve to rotate therewith and a drive rod connecting said eccentric and the arm on said switch.

5. An automatic sampling device for use in obtaining samples of a fluid flowing through a pipe line at intervals the frequency of which vary in accordance with the flow rate through said pipe line, comprising a draw-off line connected to said pipe line, a valve in said draw-on line, electrical actuating means for said valve, a rotating face meter responsive to the flow through said pipe line, a source of electricity, an electrical circuit connected to said valve actuating means, a primary switching device for intermittently closing said circuit to connect said source to said valve actuating means, said primary switching device including a pen arm on said meter, a plurality of contacts on the rotating face of said meter, a tiltable mercury switch normally biased to its open position and connected in said circuit between said source and saidvalve actuating means, an electro-magnet adapted when energized, to tilt said switch to its closed position, and means for energizing said magnet when said pen arm engages one of said contacts, and a secondary switching device for maintaining said circuit closed for predetermined intervals after it is first closed by said primary switching device, said secondary switching device including a second tiltable mercury switch connected in parallel to said first mentioned mercury switch, an arm on said second switch, and means for tilting said second switch comprising an eccentric connected to said valve to rotate therewith and a drive rod connecting said eccentric and the arm on said second switch.

GEORGE C. FAIRBAIRN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,649,399 Gard Nov. 15, 1927 2,183,338 Slough Dec. 12, 1939 2,245,679 Kelley June 1'7, 1941 2,418,876 Grace, Jr Apr, 15, 1947 

